1. Field of the Invention
The present invention relates to a lighting device using a field-emission type electron emitter.
2. Description of the Prior Arts
There has conventionally been proposed a lighting device, for example, disclosed in Japanese Unexamined Patent Application No. HEI10-255699 as a lighting device using a field-emission type electron emitter. This lighting device has a pair of flat glass substrates in a vacuum sealing tube, wherein an electron emitter (cathode section) is provided at one of the flat glass substrates and a phosphor-coated transparent electrode film (anode section) is provided at the other flat glass substrate. It is configured such that electrons emitted from the cathode section collide with the plane phosphor to excite the phosphor, thereby emitting visible light in one direction in a plane manner. This lighting device is utilized for a flat display or the like. It has been considered that the lighting device described above is utilized as a so-called backlight device that illuminates a liquid crystal panel from its backside. However, a demand for reducing a size or reducing power consumption has been more and more increased recently in an electronic device into which a liquid crystal display panel is incorporated, such as a liquid crystal television set. Therefore, the above-mentioned lighting device using the electron emitter is required not only to be capable of emitting light in all directions, not in a plane direction, but also to be capable of coping with a thin size that can be incorporated in the narrow backside of the electronic device and emitting light with high intensity even with reduced power consumption, when it is incorporated into the electronic device as the backlight device.